Regarding the Green Dye near SD
From the Coast Guard:
Good afternoon, Mr. Hellerstein,
I researched information regarding the green dye. On February 4, Sector San Diego responded to a report from aircraft of green dye which plots close to the possible lat and long given in the internet posting. They confirmed green dye 12 nautical miles offshore from Mission Bay. They did not see any debris, persons, vessels, or signs of capsized/sunken vessels in the area and suspended their search. It is important to note that Avalon Harbor places green dye in the ballast tanks of commercial vessels when they anchor in Avalon Bay. When these vessels depart for sea and pump their ballast tanks, it could be mistaken as a distress sign. I hope this helps you in your efforts.
Regards,
LTJG Nephtwim Rosario
Sector Duty Officer
Sector San Francisco
February 6th, 2007 at 3:51 pm
I’m certainly no expert on the fluid dynamics of dye dumping, but it seems to me that a large container vessel dumping a ballast tank full of green fluid would create:
1. A much larger green field.
2. A much less contiguous and geometric green field. (The wake of the boat and turbines would disperse the color more.
February 6th, 2007 at 4:28 pm
Agree with Dan, and also my estimation for the distance between the green spot and Mission Bay is 153 nautical miles, not 12. Probably it was an other spot.
February 6th, 2007 at 6:15 pm
I wanted to find out how long a dye marker will last in the water. I tried calling the manufacturer of what seems to be the most popular marine dye marker, Orion. I got very little information from them. The most they could tell me is that one 1 ounce tube will emit at least 50 square feet of fluorescein. A retail site claims one ounce will cover UP TO 250 square feet.
I contacted a friend who is a retired coast guard officer, and he told me that the dye marker will last 1 to 2 days in the water.
I will update if I get anymore information on the dye marker. I have to check with the maritime safety folks to see if they have any more precise specifications.
February 6th, 2007 at 6:47 pm
Update from USCG, in response to Dan and Istvan’s concerns:
Mr. Hellerstein,
I contacted Sector Los Angeles/Long Beach regarding this matter. They also responded to a report of green dye on January 21, 2007 which they confirmed was dye from an aircraft marker bag. No vessels or debris were sighted and they have not received any further reports of green dye. The position of the marker was 33.3 N 118.05 W, nearly correlating to the given position on the posting. Let me know if you have any further questions.
Regards,
LTJG Rosario
February 6th, 2007 at 7:06 pm
I don’t think this is right. 118W is not “nearly correlating” witth 120W. I believe the difference is about 130 miles. Can we confirm the error bound in our estimate?
I think these are two different things… the 120 miles about matches the point above that it is not 12 m offshore but 150 or so.
Perhaps they do not expect our level of precision???
-Eric
February 7th, 2007 at 5:36 am
Thanks Eric. Good work all. CG responded, see below. However, the working theory from our drift modelers and imagers is that if Tenacious is afloat, she’s far far to the north of this, so at this point I think we’ve got to leave this to USCG to pursue.
—
Joe
The marker reported in the posting is most likely not the same green dye viewed by Sector LA/LB. That being said, Sector LA/LB does have the information and will make the decision on how to proceed.
LCDR Copley
February 7th, 2007 at 5:42 am
Concerning the second reply, the date is different, too. January 21 is 11 days before Feb. 1 when the DG images were taken. Taking just the everyday experience of diffusion dyes cannot be visible and that much localized after more than a week. Alainna’s post confirms this and this site http://www.landfallnavigation.com/-sfdye.html claims just 30-40 minutes.
February 7th, 2007 at 6:32 am
I agree with Istvan; there’s no way that the dye marker would last a week. I’m sure that the coast guard is aware that a dye marker wouldn’t last that long, either, so I am not sure I understand their response.
Does anyone have an estimation of how big that dye mark is?
February 7th, 2007 at 7:06 am
I am trying to figure out what this green neon dye looks like spectrally (beyond just the green description). Anybody has a clue as to where I could find this information ? What is it made of, what are the constituents ?
Thanks,
Igor.